Constans AE3 Thessalonica mint, 337-350 AD. 23.5 mm. 6.09 g.
 
DN CONSTANS PF AVG, pearl-diademed, draped and cuirassed bust right.
FEL TEMP REPARATIO, Emperor in military dress standing left on galley, holding phoenix and labarum. Victory sitting at the stern, steering the ship. 
Mintmark TESB. 

RIC VIII Thessalonica 109.

With permission of Eidmar auction 3, lot 663 (on biddr.com), March 2024.

Note from Dane: There are two references for these
coins, depending on the size:
RIC VIII Thessalonica 109, common, 22-23 mm
RIC VIII Thessalonica 120, common, 17-19 mm
These sizes are for full flan examples.